1. Field of the Invention
The present invention relates generally to contact members and connectors, and more particularly to a contact member used in, for example, part of a connector for an IC package (an IC package connector) used in mounting an LGA (Land Grid Array) or BGA (Ball Grid Array) IC package on a circuit board and to a connector including the contact member.
2. Description of the Related Art
An IC package connector is used to mount an LGA or BGA IC package in an easily replaceable manner. The IC package connector is required to be more reliable with a recent increase in the size and speed of data transmission. An increase in data transmission speed makes it necessary to consider the effect of contact inductance. In recent years, the data transmission speed is on the order of magnitude of 10 Hz, so that the inductance of contacts in the IC package connector is required to be on the order of magnitude of 1 nanoHenry (nH) in order for data to be normally transmitted. Further, the contacts are required to be elastically deformable when in use. Further, the contacts are required to be reduced in size so as to correspond to the pad arrangement pitch of the IC package.
FIGS. 1A and 1B are diagrams showing a conventional contact member 1. The contact member 1 has a helical volute spring structure with multiple turns. When in use, the contact member 1 is compressed to generate a repulsive force with a helical signal transmission channel.
For conventional art, reference may be made to the following, for example.
[Patent Document 1] Japanese Laid-Open Patent Application No. 56-8837
[Patent Document 2] Japanese Laid-Open Patent Application No. 2001-235486
[Patent Document 3] Japanese Laid-Open Patent Application No. 2005-129428
However, although generating a resilient repulsive force, the contact member 1 shown in FIGS. 1A and 1B is not low in inductance because of the helical signal transmission channel, thus being unsuitable for a point of high-speed data transmission. Further, since the contact member 1 is not small, the contact member 1 is not suitable as a contact member for a connector whose contact members are required to be arranged with a small pitch, such as an IC package connector.